Unit 3: Chapter 24 Flashcards
Mycology
Study of fungi
6 major groups evolutionary defined by
Phylogenetic analysis
Mycologists
Scientists who study fungi
Mycotoxicology
Study of fungi toxins and their effects
Mycoses
Diseases caused by fungi
Who are the main decomposers?
Fungi
Fungal distribution
Saphrophytes
Osmotrophy
Decompose complex organic material to simple organic compounds
Showcase nutrient recycling with release of molecules for living organisms to use
Pathogens for plants and animals
Symbionts with plants
Fungi environmental conditions
Acidic condition with pH 5
Grow in high sugar and salt concentration; resistant to osmotic pressure
Can grow in low moisture content
Can metabolize complex carbohydrates
Fungal Vegetative structure
Thallus
Hyphae
Mycellium
Yeast
Mold
Cell Wall
Thallus
Body or vegetative structure of fungus which has hyphae to form mycellium for absorption of nutrients
Mycellium
Network of hyphae to help obtain nutrients
Mold
Multicellular masses
Yeast
Single celled fungi generally larger than bacteria
Cell Wall of Fungi
Composed of glucans, mannans, glycoproteins, and chitin
Dimorphic Fungi
Exhibit two morphology fungi
Ex. exists in two forms yeastlike/ unicellular form and moldlike/ multicellular form
Canandida albicans
Showcases dimorphic fungi
produce yeast
Coenocytic hyphae
No cross walls
Septate hyphae
Have cross walls called septate
Pores enable cytoplasmic streaming
Fungi Reproduction
Performs sexual and asexual reproduction
Reproduction by formation of spores that detach from parent and germinate into and a new mold
Asexual reproduction
Parent cell undergoes mitosis and divide into daughter cell
Asexual spores include
Sporangiospores, Conidiospores, Anthrospores, Blastospores
Sporangiospores
Develop within a sporangium sac at hyphae tip
Conidiospores
Spores not enclosed in sac but produced at tips or sides of hyphae
Arthospores
Formed when hyphae fragment
Blastospores
Produced from a vegetative mother cell budding
Sexual Reproduction
Involves fusion of nuclei from 2 opposite mating strains
Importance for Fungal spores
Enable fungi to survive environmental stresss
Aid in fungal dissenination
Reproduction
Useful for identification of fungal species
3 Phases of sexual reproduction
- Haploid donor cell nucleus penetrates cytoplasm of recipient cell
- Fusion of nuclei and form diploid zygote
- Meiosis: diploid nucleus produced haploid nuclei (sexual spores)
Zoosporic Fungi
Performs asexual reproduction (spornagiospores) and sexual reproduction (zygospores)
Produce motile spores
2 Groups:
1. Microsporidia
2. Chytridomycota (Chytrids)
Microsporidia
Under Zoosporic Fungi
Obligate intracellular parasite
Polar tube for host invasion and piereces
Lack mitochondria and have mitosomes
Chytridiomycota (Chytrids)
Saprophytic
Most are aquatic
Parasites and kill amphibians
Zygomycetous
No motile flagella and rely on wind or cling to animals for spore dispersal
Sexual reproduction when environmental conditions are not favorable
Zygospores (sexual spores)
Hyphae lack septate (coencytic: no cell wall)
2 Groups of Zygomentous
- Mucoromycota
- Glomeromycotina
Mucoromycota
under Zygomycetous
Used in food industry and cause food spoilage
Used to produce anesthetics, birth control, alcohols, meat tenderizers, and yellow food coloring
Genus Rhizopus
Under Mucoromycota and Zygomycetous
Grow on surface of moist carbohydrate rich foods (bread, fruit, vegetables)
Hyphae absorb nutrients
Asexual reproduction and if environemntal conditions unfavorable do sexual reproduction
Plasmogamy
Fusion of cytoplasm of 2 genetically different cells (+ and -)
Karyogamy
+ and - nuclei fuse and form diploid zygote
Meiosis
Diploid nucleus produces haploid nuclei (sexual spores)
Rhizopus Chineosis
Under zygomycetous, mucoromycota
Seedling blight rice disease
Glomeromycotina
Under zygomycetous, mucoromycota
Symbionts of plants: FDungus deliver nutrients to plants and plants provide carbohydrates to fungus
Mycorrhizal fungi: grow in association with their roots of their plant hosts
Dikarya
most diverse funagl growth
Have septate hyphae (have cross walls)
cell membrane has sterol ergosterol (drug target)
delay in fertilization with dikaryotic stage: n+n before going to 2 haploid nuclei
2 Taxa of dikarya
- Asycomycota (sac fungi)
2.. Basidomycota (club fungi)
Ascomycota (sac fungi)
Dikarya
Has ascospores for reproductive spores
Ex. Aspergillus
Aspergillus
Fungi that causes Aflatoxin and cancer
Basidiomycota (club fungi)
Dikarya
Sexual spore: Basidiospore
Fragmentation
Has septate (cross walls)
Mushroom and plant pathogens which produce toxins
Sacchromyces cerevisiae
brewer’s yeast